Mechanical control for ice level in storage bin



G. K- WRIGHT Nov. 29, 1960 MECHANICAL CONTROL FOR ICE LEVEL IN STORAGE BIN 3 Sheets-Sheet 1 Filed Sept. 4, 1956 a ziw FIG.

INVENTOR. GORDON K. WRIGHT.

FIG. 6

AT TORNEY.

G. K. WRIGHT MECHANICAL CONTROL FOR ICE! LEVEL IN STORAGE BIN Filed Sept. 4, 1956 3 Sheets-Sheet 2 INVENTOR.

GORDON K. WRIGHT.

ATTORNEY.

Nov. 29, 1960 G. K. WRIGHT 2,961,842

MECHANICAL CONTROL FOR ICE LEVEL IN STORAGE BIN Filed Sept. 4, 1956 3 Sheets-Sheet 3 1 53 6| i I FIG. 5

FIG. 4

INVENTOR.

GORDON K. WRIGHT.

ATTORNEY.

United States Patent MECHANICAL CONTROL FOR ICE LEVEL IN STORAGE BIN Filed Sept. 4, 1956, Ser. No. 607,827

12 Claims. (Cl. 62-137) This invention relates to an improved electro-mechanical control for starting and stopping the icemaking operation of an automatic ice making machine in response to the depth of ice in the ice storage bin of the machine.

The present invention, while applicable to various types of ice making equipment, is particularly adapted for use in flake ice machines of the type wherein ice is formed by freezing water on the surface of a cylinder .and the ice is removed from the cylinder in flake form "by a rotating blade. The flake ice which is thus formed idrops into a storage bin from which it is removed for use as desired. A machine of this general type is fully described in the copending application of David Earle Mac- Leod and William W. Bell, Jr., Serial No. 538,204, filed October 3, 1955, now abandoned.

In icemaking machine's it is desirable to fill the storage bin to a predetermined level'and then automatically stop the icemaking operation. As the ice in the bin is depleted, it is desirable to automatically resume the icemaking operation until the'desired level is again attained.

To achieve the foregoing cycle of operation a thermostatic control has been employed in the past. This controlis placed at a desired level in the storage bin and, in response to the temperature at that level, starts or stops the icemaking operation. The theory of operation of this control is that when the ice reaches a desired level so .that its sensing element is in contact with ice, it will stop -the icemaking operation.

It has been found, however, that the thermostatic control has serious disadvantages which render it impractical 'and inefl'icient. In the first place, the control is normally setto stop operation of the machine when the temperature of the sensing element is 34 F., i.e. when it is in contact with both the ice and the air in the bin. How ever, when subcooled ice is being made, as described in the above-mentioned copending application, or when there is a low ambient temperature, the temperature of the air above the ice level in the storage bin can fre- 'quently drop to 34 F., before the bin is full. Thus the storage bin maybe only partially full when the machine is shut off, and this may result in shortages of ice when -"it is needed. Furthermore, the bin temperature in the vicinity of the control sensing element may frequently be above 34 F., the desired cutout temperature, as a result of a high'ambient temperature even when the bin is full. in such a case, the icemaker will unnecessarily continue to operate after the bin has been filled with the attendant possibility of clogging the machine.

Another disadvantage of the thermostatic type of cont'rol'eleinent is that the icemaking operation will be prematurely stopped if the control is splashed with cold water or has ice particles adhering to it. Thus the ice .in the storage bin may be depleted below the desired level without resuming the icemaking operation. Furthermore, even if the sensing element is operating according to its theoretical optimum mode of operation, there is usually an inherent delay in its operation in the sense thatit will not warm up quickly enough to resume the s 2,%l,842 C Patented Nov. 29, 1960 icemaking as soon as the ice in the storage bin is depleted. Thus there may be a critical lag in the making of ice in periods of great demand. It has also been found that low barometric pressure will cause the machine to continue operating after the desired level in the ice storage bin has been reached.

There are also certain inherent drawbacks to the physical construction of the thermostatic sensing element and its associated structure. A capillary tube leading to the sensing element is fragile and therefore subject to breakage. Furthermore there is the constant possibility of losing the fluid charge from the thermostat thus rendering the entire control inoperative.

In order to eliminate the above-discussed shortcomings and disadvantages which are inherent in the use of thermostatic controls, I have devised a simple mechanical control which can be easily installed in existing flake ice machines of the type described in above-mentioned application, Serial No. 538,204. This mechanical control, in addition to being positive and efficient in its operation, has the advantages of being simple in construction and inexpensive to manufacture.

The present invention consists of a mechanical sensing element which is adapted to be physically displaced as the ice level in the storage bin rises. When the ice reaches a predetermined level, the sensing element actuates an electrical switch to stop the icemaking operation. More specifically, the electro-mechanical control of the present invention consists of a shaft extension and associated structure, said shaft extension being coaxially attached to the rotating vertical shaft which mounts the ice :removiug blade. The sensing portion of the control ex- .tends into the ice storage bin and comprises a sleeve mounted on said shaft extension for both rotary and longitudinal movement relative to said shaft extension. Affixed to the lower portion of said sleeve is a downwardly curved shield which lies in a lowermost position when the ice in the bin is below the desired level and in an uppermost position when the ice has reached the desired level. In the lowermost position the apex of the shield rests on cam structure which is aflixed to the shaft extension. As the ice level rises, it contacts the shield and causes it to rise. This in turn causes a collar affixed to the top of the sleeve to trip a switch which stops the machine. More specifically as the ice level rises into contact with the shield, the latter encounters resistance to rotation and the cam structure will then start rotating relative to the shield and cause it and the sleeve afiixed thereto to rise. When the sleeve rises it actuates the switch which turns off the machine. As the ice level in the bin falls below the desired level, the shield will drop by gravity and release the switch, this in turn starting the icemaking machine.

In the light of the foregoing it is the main object of this invention to provide an electro-mechanical control for an icemaking machine which will positively start and stop the icemaking process in response to the level of ice in the bin.

I control for an icemaking machine which in addition to being positive and efiicient in operation, also is simple in construction and relatively inexpensive to manufacture.

Other objects of the present invention will become readily apparent when the following portions of'the specification are read in conjunction with the drawings wherein:

Figure l is an elevational diagrammatic view of a flake icemaking machine, partly in section, with the electromechanical control attached;

Figure 2 is an enlarged portion of Figure 1 with certain parts omitted which shows the position of the control before the ice in the bin has reached the desired the machine and thereby controls their operation.

Referring to the drawings, there is shown in Figure l a flake ice making machine having an ice making section which is mounted on ice storage section 11. The ice making section 10 consists of a cylindrical drum 12 having concentric metallic inner wall 13 and outer wall 14, these walls being separated by suitable insulation 15. The

ice making section 10 is provided with a top 16 on which is mounted motor 17, the shaft of which is coupled to gear reducer 18. Shaft 19 is concentrically positioned within cylindrical drum 12 and is driven by gear-reducer 18. The drum 12 is mounted on an intermediate support member 20 and secured thereto by a suitableangle member 21 (connecting members not shown). The support member 20 is in turn mounted on frame 22, which in turn is-mounted on ice storage section 11.

The upper portion of shaft 19 is journalled in bearing 23 which is in turn mounted on drum 12 by radial webs 24 which extend between cylindrical surface 13 and bearing 23. The lower portion of shaft 19 is journalled in bearing 25 which is supported by webs 26 affixed to frame 20.

Fixedly mounted on shaft 19 and extending radially therefrom is web 27 which detachably mounts ice removal blades 28 (connections not shown). As the shaft 119 rotates the blades 28 aid in the removal of ice which i formed on cylindrical surface 13 in the manner set forth in the above-mentioned copending application. A followup blade 29 is also detachably mounted on web 27 (connections not shown) to scrape ice from the cylindrical surface 13 which has not been completely removed by ice removal blades 28. It can readily be seen from Figure 1 that since shaft 19 rotates in the direction of the arrow that follow-up blade 29 contacts a given point on the cylindrical surface 13 after blades 28 have passed this point.

A refrigeration system is incorporated into the icemaker, as shown in Figure 1, for the purpose of forming ice on the cylinder wall 13. This ice is formed from wa ter which is supplied to cylinder wall 13 in a manner to be fully described hereafter, and the ice is preferably subcooled as described in the above-mentioned application, Serial No. 538,204. The refrigeration system consists of a compressor unit 30 which compresses the refrigerant and supplies it to a water-cooled condenser 31. Water is supplied to condenser 31 through line 32 from a main water supply line 33. The condensed refrigerant passes from condenser 31 to strainer-dryer 34 and then through line 35 and expansion valve 36 to evaporator coil 37 which is wrapped around cylindrical wall 13 for the purpose of cooling it. The refrigerant vapor is withdrawn from evaporator 37 through suction line 38 and passed to compressor 30 to complete the refrigeration cycle.

Ice is formed on the internalportion of cylinder wall 13 according to the followingprocedure. Water is passed from the main water supply line 33 via line 39 into sump 40. The water is sump 40 is maintained at a predetermined level by float 42 which controls valve 41. A motor 43 runs pump 44 to cause water to flow from sump 40 through pipe 45 into a-torus shaped distributing tube 46. Perforations (not shown) are formed in tube 46 to allow water to flow at'a required rate on to a distributor'plate 47 which is mounted on shaft 19 for rotation therewith. Distributor plate 47 is generally of slight conical configuration, as shown in Figure 1, so that water can flow down its inclined surface and on to cylinder wall 13 from its outer edge 48. It is to vbe noted that if the ice which is to be formed on cylinder wall 13 is to be subcooled, plate 47 may have a portion of its outer periphery blocked by a barrier 49, as fully described in above-mentioned application Serial No. 538,204, so that water is supplied from plate 47 to cylinder wall 13 in less than a 360 are. In this manner the ice which is formed on cylinder wall 13 is allowed to subcool before it is harvested by blades 28 because the blades are located under the blocked portion of the distributor plate 47 thus giving the ice which has formed on the cylinder wall time to subcool.

During the ice making operation, a certain amount of water will not be frozen but will run down the entire length of cylinder wall 13. It is undesirable to have this water dn'p into the ice storage bin. Therefore an annular channel-shaped trough 50 ispositioned under the lower outwardly flaredportion 51 of cylinder wall 13 .to catch thisexcess water and return it to sump 40 via pipe 52 connected totrough 50. It is to be noted that it is undesirable to have flakes of icefall into trough 50. The outward flare 51 allows, annular trough 50 to be positioned outside of the path of the falling ice. The water which runs down cylinder wall 13 will adhere to outward flare 51 because of surface tension and fall into trough 50.

Reference is now made to Figures 1, 2 and 3, which show the orientation of the-improved control of the present invention relative to the above-described flake ice machine. The sensing element 53 consists of a shaft extension 54 which has a disc shaped mounting flange 55 formed at its upper end. Suitable screws or the like (not shown) are used to attach flange 55 to the lower end of shaft 19 to cause shaft extension 54 to rotate therewith. The lower end of shaft extension 54 has an inverted channel 56 (Figure 5) fastened thereto, as by welding. A horizontal axle 57 ha its central portion located within channel 56, and is secured to said channel by cotter-pin 58 which extends through aligned holes (not numbered) in said members. Because of this connection, axle 57 can pivot slightly within channel 56 so that cams 59 which are journalled at the ends of axle 57 will tend to remain in contact with shield 60 as they move relative to said shield notwithstanding any slight improper curvature of shield 60.

In the operation of the control, cams 59 cooperate with downwardly curved shield 60 to sense when the ice in storage bin has reached a predetermined level. Shield 60 is atiixed to the lower portion of sleeve 61 which is mounted on shaft extension 54 for longitudinal and rotary movement relative thereto. As the flake ice fills the storage bin so that it approaches the desired depth, shield 60, which normally rests on earns 59 as shown in Figure 4, tends to rise on theice. In so doing, it moves sleeve 61 upwardly with it. Affixed near the top of sleeve 61 is collar 62 which contacts arm 63 of switch 64 as sleeve 62 approaches its uppermost position. When the ice in the storage bin 11 has reached the desired height, switch 64 is moved to such a position that it breaks the flow of current to the various motors in the system and stops the icemaking operation.

. It is to be noted that the sensing element 53 rotates in the same direction as shaft 19, that is, in the direction of the arrows in Figures 4 and 5. In order to prevent the shield 60'from slicing through the icein the bin, upwardly turned fins 64 are formed on the edges of shield60 which lead into the ice, (Figures 4 and 5). These fins also facilitate the shields riding over small projections of ice. Downwardly turned fins 65 are formed on the trailing edges of shield 60 to arrest rotary movement of the shield 60 relative to the ice. When there is suificient resistance to the rotary movement of shield 60, shaft extension 54 and cams 59 will rotate relative to shield 60. Thus cams 59 will move from the apex of shield 60 (Figure 4) to the position shown in Figure 5. In so doing, shield 60 will ride upwardly on cams 59 and cause collar 62 to abut switch arm 63 turning off the current to the various motors of the machine.

Figures 2 and 3 show the positions of the sensing element 53 when the ice in the storage bin is below and at the desired levels, respectively. During the ice making operation, the elements are in the position shown in Figure 2. However, when the ice in storage bin 11 has reached the required level, the sensing element assumes the position shown in Figure 3. As ice is removed from door 66 in storage bin 11, the ice level in the bin will drop. When this occurs, shield 60' will fall by gravity relative to both shaft extension 54 and cams 59 and release arm 63 of switch 64. When this occurs, the icemaker will again start making ice until the bin has been filled to the desired capacity.

It is shown in Figures 2 and 3 that switch 64 is mounted in a housing 67 which is suitably attached to web 26 by bracket 68. Housing 67 protects switch 64 from water dripping from web 26 and from being jammed or broken by ice 69' which is removed from cylinder wall 13- during the icemaking operation. It is to be further noted that switch 64 is mounted within housing 67 at an angle to the horizontal (Figures 2 and 3),'and that switch arm 63 extends downwardly from switch 64. Because of this arrangement, any condensate which forms on the switch' and switch arm will flow away from rather than toward the switch. Bracket 101 causes lead wire 102 to be bent in a U-shape around the bottom of housing 64 to prevent condensate from running along wire 102 into the switch. A shield 76 is mounted on shaft 19 to deflect dripping water and falling ice and thus protect bearing 25 and sensing element 53 from damage.

It can be seen from Figures 2, 3 and 6, that if sleeve 61 should ride up too high on shaft extension54 for any reason that there is a possibility of doing damage to switch 64 by forcing arm 63 beyond its normal travel. In order to prevent such undesired movement, a cotter-pin 71 is positioned in a hole (not numbered) in shaft extension 54. This cotter-pin is abutted by collar 72 of sleeve 61 when the latter is in its uppermost position and thus defines the limit of upper movement of sleeve 61. It can be seen from Figure 5 that cotter-pin 71 also prevents shield 60 from rising to the extent where cams 59 come to rest in a dead-center position on the longitudinal center line of shield 60. Thus when the icelevel falls out of contact with shield 60, it is assured that the shield will rotate and move downwardly relative to shaft extension 54 because of gravity to assume the position shown in Figure 4.

Figure 6 is a schematic wiring diagram of the electrical circuit of the invention. Switch 64 is connected in series with Water pump motor 43-, shaft-driving motor 17, and compressor motor 30. When the ice storage bin 11 is full switch 64 opens in the manner described, preventing the flow of current to the above-enumerated motors. When the ice level in the bin 11 falls so that collar 62 ceases to abut switch arm 63, a spring (not shown) biases switch 64 to the On position and the ice making process is resumed.

In summary, the operation of the present electromechanical control is as follows: before the ice level in the storage bin has reached the desired level, the sensing element 53 will rotate as a unit with shaft 19. When shield 69 encounters the resistance of the rising ice level,

shaft extension 54 andv its attached earns 59 will rotate relative to shield 60 and cause it to rise. The collar 62, which is mounted on sleeve 61, will also rise and con tact arm 63 of switch 64 thus breaking the electrical circuit shown in Figure 6 and stopping the machine. When the level of ice in the storage bin is reduced from its maxi mum height, shield 60 and sleeve 61 will rotate relative to shaft extension 54 so that shield 60 will drop and come to rest with cams 59 in its apex. In this position, collar 62 on sleeve 61 releases arms 63 of switch 64 which in turn causes current to be supplied to the various motors of the ice maker so that ice making is resumed.

I have thus described a preferred embodiment of my invention. However, as noted above, while I have described the present invention with respect to a flake ice machine, it is understood that the invention is not limited thereto since it may be otherwise embodied relative to other types of icemaking machines within the scope of the following claims.

I claim:

1. An electro-mechanical control for sensing an accumulation of ice of a predetermined magnitude in the storage bin of an icemaking machine having a rotatable shaft comprising a shaft extension adapted to be affixed to said shaft for rotation therewith, a movable member mounted on said shaft extension for movement relative thereto when said movable member comes into contact with ice in said storage bin, means for moving the movable member relative to said shaft extension when the movable member comes into contact with ice in the storage bin, and a switch mounted on said machine adapted to be engaged by said movable member to cause said machine to cease operation when the ice in said storage bin is at a predetermined level.

2. An electro-mechauical control for sensing theful lness of the storage bin of a flake ice machine having a rotatable shaft comprising a shaft extension adapted to be affixed to said shaft for rotation therewith, a movable member mounted on said shaft extension for rotary and axial movement relative thereto when the rising ice level in the storage bin comes into contact therewith, means for moving the movable member axially of said shaft extension when the movable member comes into contact with ice in the storage bin, and a switch mounted on said machine adapted to be actuated by the movement of said movable member to stop said machine when said movable member senses the ice in said bin to be at a predetermined level and to start said machine when said movable member senses the ice to be below said predetermined level. I

3. An electro-mechanical control for stopping or starting the operation of an icemaking machine having a rotatable shaft when the ice level in the storage bin of said machine rises to or falls below a predetermined level, respectively, comprising a shaft extension adapted to be affixed to said shaft for rotation therewith, a movable member mounted on said shaft extension for movement relative thereto when in contact with the rising or falling ice level in said bin, means for moving the movable mem ber relative to said shaft extension when the movable member comes into contact with ice in the storage bin, and a switch mounted on said machine adapted to be actuated by said movable member to stop said machine when said movable member rises in response to the ice in said bin reaching a predetermined level and to start said machine when said movable member falls in response to the ice dropping below said predetermined level.

4. A control as set forth in claim 3 wherein said movable member comprises a sleeve mounted on said shaft extension for rotary and axial movement relative thereto, a shield member atfixed to one end of said sleeve, and mean-s at the other end of said sleeve for selectively engaging said switch, said shaft extension, sleeve, and shield rotating as a unit when not in engagement with the ice in said storage bin.

5. A control as set forth in claim 4 wherein said means for selectively engaging said switch comprises a collar affixed to said sleeve.

6. An electro-mechanical control for stopping or starting the operation of an icemaking machine having a rotatable shaft when the rice level in the storage bin of said machine rises to or falls below a predetermined level, respectively, comprising a shaft extension adapted to be afiixed to said shaft for rotation therewith, a movable member mounted on said shaft extension for movement relative thereto when in contact with the rising or falling ice level in said bin, and a switch mounted on said machine adapted to be actuated by said movable member to stop said machine when said movable member rises in response to the ice in said bin reaching a predetermined level and to start said machine when said movable member falls in response to the ice dropping below said predetermined level, said movable member comprising a sleeve mounted on said shaft extension for rotary and axial movement relative thereto, a shield member affixed to one end of said sleeve and means at the other end of said sleeve for selectively engaging said switch, said shaft extension, sleeve and shield rotating as a unit when not in engagement with the ice in said storage bin, said means for selectively engaging said switch comprising a collar afiixed to said sleeve and cam means affixed to said shaft extension for engaging said shield so that when rotary movement of said shield is impeded upon contact with ice in the bin said cam means will cause said movable member to move to actuate said switch 7. A control as set forth in claim 6 wherein said shield is curved to form a cam track and said cam means are mounted on a member which is atfixed to said shaft extension.

8. A control as set forth in claim 7 wherein said shield has leading edges and trailing edges and upwardly turned fins formed on the leading edges thereof which rotate into said ice to facilitate rising of said shield on said ice.

9. A control as set forth in claim 8 wherein said shield has downwardly turned fins on said trailing edges thereof to impede rotary movement of said shield with said shaft extension when said shield is in engagement with said ice whereby said cam will move relative to said shield and will cause said sleeve attached to said shield to actuate said switch.

10. A control as set forth in claim 9 including means mounted on said shaft extension to limit the travel of said sleeve.

11. A flake ice machine comprising a frame, a cylinder mounted on said frame, means for placing a film of water on said cylinder, refrigerating means surrounding said cylinder for freezing said water, a rotatable shaft operatively mounted on said frame in concentric relation to said cylinder, blade means mounted on said shaft for traversing said cylinder as said shaft rotates to remove said ice from said cylinder, an :ice storage bin positioned 8 under said cylinder for storing said ice, and an electromechanical control element including a movable member affixed to said shaft, said movable member being adapted to rise when contacted by the rising ice level to stop said machine, said movable member being adapted to fall as the ice level in the bin falls to start said machine, said electro-mechanical control comprising a shaft extension affixed to said shaft for rotation therewith, said movable member being mounted on said shaft extension and being adapted to move when in contact with the rising and falling ice level, means for moving the movable member relative to said shaft extension when the movable member comes into contact with ice in the storage bin, and switch means responsive to movement of said movable member to cause said machine to cease operation when said movable member senses the ice lll'l said bin to be at a predetermined level and to cause said machine to start operation when it senses the ice to be below said predetermined level.

12, In a machine for making ice flakes, the combination of a cylindrical ice accumulating surface, means for distributing water over said surface, means for freezing said water on said surface to form ice, an ice removing blade arranged relative to said cylindrical surface to remove ice therefrom, a bin positioned relative to said surface to store said removed ice, and electro-mechanical means including a movable member adapted to rise and fall with the rising or falling ice level for stopping or starting said machine when the ice level in said bin is at or below a desired level, respectively, said ice removing blade being mounted on a rotating shaft and said electro-mechanical means comprising a shaft extension afiixed to said shaft for rotation therewith, said movable member being mounted on said shaft extension, means for moving the movable member relative to said shaft extension when the movable member comes into contact with ice in the storage bin, and a switch mounted on said machine adapted to be actuated by said movable member to cause said machine to stop when said movable member rises in response to the ice in said bin reaching a predetermined level and to start said machine when said movable member falls in response to the ice falling below said predetermined level.

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